kartik\select2\Select2::run PHP Method

    public function run()
    {
        parent::run();
        $this->renderWidget();
    }

 public function run()
 {
     echo '<form id="form1" data-pjax-exclude method="GET">';
     parent::run();
     echo '<div class="form-group"><div class="col-lg-11">';
     echo Html::submitButton('Select users', ['class' => 'btn btn-primary']);
     echo '</div></div></form>';
 }